Question

In an agitated vessel, baffles are mainly designed to

• A. Bubble Breakup Reduction.
• B. Better Mixing.
• C. Low Power Consumption.
• D. High Heat Transfer.

Hint:

Baffles are the most common way to eliminate a vortex in a stirred tank. While they increase the power required for agitation, the trade-off is a much more homogenized mixture.

Answer 1

The Correct Option is B

Concept: Baffles are stationary plates attached to the inner walls of an agitated tank to modify the flow patterns created by the impeller.

Step 1: Understanding flow patterns.
In an unbaffled vessel, the rotation of the impeller creates a tangential flow or "swirl." This often leads to a central vortex and "solid-body rotation," where the fluid spins as a mass without significant relative motion between layers.

Step 2: Role of baffles in mixing.
Baffles disrupt this tangential swirl and convert it into axial and radial flow patterns. This increase in turbulence and top-to-bottom turnover ensures a more uniform distribution of materials, resulting in significantly better mixing efficiency.